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FRED. VW. SMITH, OF FREEPORT, ILLINOIS, ASSIGNOR TO PURINTON 8a SMITH, OF SAME PLACE.

DOOR-SPRING.-

SFECIFICATION forming part of Letters Patent No. 235,582, dated December 14. 1880.

Application filed September 23, 1880.

To all ywhom 'it may concern Be it known that I, FRED. W. SMITH, a citizen of the United States, residing at Freeport,

in the county of Stephenson and State of Illinois, have invented new and useful Improvements in Door-Springs, of which the following is a specification.

My invention consists of an arrangement whereby a door-spring acting on the torsion principle is made not only to close the door to which it is applied, but to also hold the door open in desired positions. It is also an improvement in tha-t the torsion is but very slightly increasedby opening the door, thus rendering the spring much more durable and effective.

All forms of torsion-springs, whether rod or spiral, as new constructed,'contemplate the rigid fastening of one end to the casing and the other end rigidly to thedoor. I design substituting for the rigid attachment on the door a swivel-eye attachment connected by an intermediate arm or crank with the end of the spring.

Figure 1 is a View of the spring in its position on a closed door. E is thedoor. D is the casing. The spring, which I show as a rod-torsion, is represented by A, and is secured at its upper end in a ratcheted hearing, d, which allows different degrees of torsion beingimparted to the spring. The intermediate arm or crank is shown in this gure as being formed at the end of rod A by being bent at the angles a and b, forming the arm A and the upward-projecting end A. This arm can also be formed by rigidly attaching a piece of the desired shape to the en d of the spring rod A.

To the casing is attached, near the arm end of the rod A, a device, B, which consists of a base-plate, c, and curved guiding-bar c. This device is shown by plan and section in Fig. 2, and in its position in relation to the spring in Fig. l. This position is at the edge of the casing near the door, the rod A passing between the base-plate c and the curved bar e. The position of the rod A (door closed) is shown by section, Fig. 2.

To the door is attached a swivel-eye, G, Fig. 1, into which the end A of the arm A is (No model.)

not only still further twisted, but also pressed backward toward the rear end of the curved bar e', the outward force causing it to follow theline of curvature. The extent to which the door is opened governs the distance which the rod A travels backward on the curved bar e. The ratchet d holding the upper end of the rod Ain a firm position, the lateral elastic force of the rod is brought into play to assist the torsion force. The pressure ot` the rod A outwardly against the curved bar c', and the pressure of the end All inwardly against the door, gives the door a closing tendency until the rod A has been pressed backward by the opening of the door the full extent ot' the large outward curve e of the curved guidingbar e. (See Fig. 2.) This will allow the door to open about one hundred and twenty degrees, or about two-thirds of a full swing. When the rod has passed the large outward curve e and moves onto the smaller inward curve e, Fig. 2, the direction of the force on the door is reversed, as the inward pressure of the end A in the eye C will be from the door toward the casing, and is exerted to draw the door toward the wall and casing.

The large outward curve e of the curved bar e is made rather abrupt at the point where the smaller inward curve c' commences. This is in order to retard the backward movement of the rod A, for the reason that the door should not be liable to be held open when hastily thrown back by having the rod A pass onto the small curve or stop on adead-center, as would be the case were the movement of the rod A too free and unimpeded. This abruptness also tends to give the door a quick strong closing impulse.

Should it be desired to have the door held open it is easily accomplished by pushing the door backward until the rod A has passed onto the small inner curve, e.

IOO

I have adopted devices, as shown, after considerable experiment, as the mostdesirable and satisfactory in their results. rilhe results I produce are entirely new as far as known to me in relation to torsion-springs, or that class of springs one end of which is rigidly attached tothe casing or door, and the other' end so attached that the opening` of the door shall twist the spring, the recoil ot' which tends to close the door. Springs so placed are subject to an undue amount of twist when the dooris thrown fully open or back to the wall, and are liable to lose their elasticity or be broken. They also force the door to close at any or all parts ot' its swing.

The results I produce with springs ot' this class can also, to a certain extent, be produced by substituting for the curved guiding-bar e and its base-plate c a supplementary bar acting between the end of rod A and a swiveleye on the casing, the end A being still thrust into the eye C on the door; or by securing the end ot rod A in a swivel-eye on the casing; also, connecting the end A to the eye C on the door by a supplementary bar.

The superiority ot' the curved bar c over the supplementary bars consists in arranging for retarding the backward motion of the rod A, and becausethe backward-sliding movement causes the lateral elastic force to re-enforce the torsion force. Either curved or supplemen tary bars will produce a reverse force, as they will allow the swivel-eye O to be brought into such a position that the pushing force of the end A" is chan ged to pulling force. It is also superior for the reason7 as stated, that the abrupt termination of the large outward curve e tends to give the door a quick strong closing impulse, and also prevents the rod A from stopping on a dead-center.

The rod A can be replaced, ifdesired, by a coil spiral spring, to one end of which an arm, A', and its upward end A, is rigidly at-` tached. A

I am aware that all springs, or nearly all, depend for their force upon the twisting ot' coiled wire or rods, an d thatarms or cranks are component parts of many; but the class ot' springs to which my improvement belongs has never, as far as known to me, been provided with any device similar or equivalent to a bar or arm, or the swivel-eye attachment on the door, but have imparted their force to the door by the arrangement ct' their ends in relation to the door and casing, being rigidly attached at both points ot' connection, being placed laterally parallel with the door, or as nearly parallel as itis possible to adjust them. Itherefore consider that the features ot' forming at one end ot' such a spring an arm or crank in such a manner that it is virtually a part of the spring, and connecting said arm to the door in such a manner that it rotates freely within its bearing, and producing on a door bot-h a pushing and a pulling motion, imparted by a spring the position ot' which is vertically parallel with the door, one end ot'which springis rigidly secured to the casing of said door, and, further, so adjusting said spring that the opening ot' the door so moves the spring that the lateral elasticity is made to re-intorce the torsion force in giving the door a closing impulse, are novel and desirable features ot' improvement.

Having thus closely and definitely described my invention and its relation to the state otl the art pertaining to the class ot' springs to which it belongs, I desire that Letters Patent be granted to me for the following:

The combination of the spring A, with its crank A and upward-projecting end A, the base-plate e, the en rved bar c', together with the swivel-eye C, arranged substantially as set forth.

FRED. NV. SMITH.

WVitnesses JNO. B. TAYLOR, FRANK W. BRAINERD. 

